Background
Treatment of hemato-oncologic patients is often associated with severe pulmonary complications. Pulmonary function is routinely evaluated in older children, whereas in young patients, forced spirometry measurements are infrequently performed. Aim: To assess severity of airway disease using forced spirometry measured prior to and after treatment (over 3 years) in hemato-oncologic children aged 3-7 years in comparison to a healthy population.
Material and Method
42-children (18-males; age 3-7 years old) with hemato-oncologic illnesses participated in the study. Spirometry was performed before the definitive treatment and up-to 3-years thereafter. Values were compared to those of healthy children of corresponding age.
Results
Most children (n=38) showed only minor long term airflow impairment (z-scores of FEV1 at last measurement was -0.00 to -0.45 SD). Prior to definitive treatment eight children presented severe airflow limitation (z-score =-1.35 + or - 0.72; -1.61 + or - 0.66 and -2.49 + or - 0.34 for FEV1, FEV0.5; and FEF25-75 respectively). Four of eight children resumed normal pulmonary function; the spirometry values of the other four children further deteriorated, in association with GVHD and development of bronchiolitis obliterans.
Conclusions
Our study suggests that it is important to follow spirometry in young children with hemato-oncologic diseases in order to detect these patients, whose condition may have prognostic implications for their treatment.

Keywords: Prevalence, Israel - epidemiology, Hematologic Neoplasms - physiopathology, Follow-Up Studies, Child, Case-Control Studies, Airway Obstruction - physiopathology, Spirometry - methods, Vital Capacity - physiology